Detergent formulations

ABSTRACT

DETERGENT FORMULATIONS COMPRISNG TETRA ALKALI METAL ETHANE TETRACARBOXYLATE AS A DETERGENCY BUILDER IN COMBINATION WITH CONVENTIONAL SURFACTANTS PROVIDE EFFECTIVE CLEANING ACTION AND ARE READILY BIODEGRADABLE.

measures" Patent Ofiice Patented Aug. 13, 1974 Int. Cl. Clld 1/04 US. Cl. 25289 3 Claims ABSTRACT OF THE DISCLOSURE Detergent formulations comprising tetra alkali metal ethane tetracarboxylate as a detergency builder in combination with conventional surfactants provide effective cleaning action and are readily biodegradable.

BACKGROUND OF THE INVENTION This invention relates to novel detergent formulations characterized by the use therein of tetra alkali metal ethane-1,1,2,2-tetracarboxylate as a detergency builder in combination with conventional surfactants.

The basic and essential ingredient of any detergent formulation is a surfactant which by reason of its surface active characteristics in solution, wetting properties, foaming properties, emulsifying action and/or other properties is effective in removal of soil or dirt.

Detergent formulations commonly contain at least one other ingredient serving as an adjuvant, re-enforcer, supplement, augmentor, potentiator and/or benefactor which serves to improve or enhance the cleansing ability of the formulation in various applications. Such other ingredients are usually referred to as detergency builders.

[n addition to providing adequate functional characteristics, it is desirable that the ingredients of detergent formulations be free of adverse ecological effects, at least in those instances where the ingredients will be released into the environment. In particular, it is desirable that organic ingredients of detergent formulations be capable of bio-degradation in conventional sewage processing operations.

SUMMARY OF THE INVENTION It is an object of this invention to provide novel detergent formulations.

.These formulations comprise a surfactant and tetra alkali metal ethane-1,1,2,2-tetracarboxylate. The tetraalkali metal ethane-l,l,2,2-tetracarboxylate in addition to providing detergency builder function is substantially totally biodegradable in activated sludge treatment such as utilized in many sewage processing operations.

The invention will be better understood from the following description of the preferred'embodiments.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The detergent formulations of this invention will contain from 1% to 60% by weight, preferably from 5% to 40% by weight, of tetra alkali metal ethane-l,l,2,2-tetracarboxylate. The tetra sodium salt is generally preferred.

The use of the specific compound defined above ap pears critical in that alkali metal salts of the adjacent homolog propane l,l,3,3-tetracarboxylic acid do not provide the advantages of this invention.

The tetra alkali metal ethane-1,1,2,2-tetracarboxylate can be utilized as the sole detergency builder in the compositions of this invention or in combination with other known detergency builders such as Water-soluble, inorganic builder salts, for example, alkali metal carbonates, borates, phosphates, polyphosphates, bicarbonates and silicates or organic builders, for example, alkali metal, ammonium or substituted ammonium, aminopolycarboxylates, salts of phytic acid, sodium citrate, water-soluble polymeric polycarboxylates as described in US. Pat. 3,308,067 and the like. Examples of such other known builders which have been extensively utilized commercially include sodium tripolyphosphate and sodium nitrilotriacetate.

The detergent formulations of this invention will additionally contain at least 8% by weight of a surfactant. Any of the numerous well-known anionic, nonionic, zwitterionic or ampholytic surfactants can be employed.

Examples of suitable anionic surfactants include alkyl ethyl sulfonates, alkyl sulfates, acyl sarcosinates; acyl esters of isethionates, acyl N-methyl taurides, and alkyl aryl sulfonates. The foregoing materials are used in the form of their water-soluble sodium, potassium, ammonium and alkyl ammonium salts. Specific examples include sodium lauryl sulfate; sodium N-methyl lauryl tauride; sodium dodecyl benzene sulfonate; and triethanol amine undecanol benzene sulfonate.

Examples of suitable nonionic detergents include alkyl phenol and alcohol alkoxylates including condensates of l-decanol or l-undecanol with from 3 to 5 molecular proportions of ethylene oxide; condensates of monohydroxy or polyhydroxy alcohols such as oleyl alcohol or l-tridecanol with from 9* to 15 molecular proportions of ethylene oxides; alkyl internal vicinal dialkoxy or hydroxy alkoxy compounds, particularly as described in US. patent application Ser. No. 136,249, filed Apr. 21, 1971 and copending herewith; and condensates of alkylene oxides with organo amines, for example, ethylene diamine and amides such as N-octadecyl diethanol amide.

Examples of cationic surfactants include octadecyl ammonium chloride; straight chain fatty amines having 8 to 18 carbon atoms; and quaternary ammonium compounds such as octadecyl trimethyl ammonium chloride.

Suitable ampholitic surfactants include the amido alkene sulfonates such as sodium C-pentadecyl, N-methyl amido ethyl sulfonate potassium C-octyl N-naphthalene amido propyl sulfonate; ammonium C-decyl, N-cyclo propyl amido butyl sulfonate, and aliphatic amine derivatives in which the aliphatic substituent contains an anionic water-solubilizing substituent such as a carboxy, sulfo, phosphato, or phosphino group, for example, sodium-3- dodecyl amino propionate and sodium-3-dodecyl amino propane sulfonate. v

Examples of zwitterionic surfactants include derivatives of quaternary ammonium phosphonium and sulfonium compounds such as 3-(N,N-dimethyl-N-hexadecyl ammonio) propane-l-sulfonate and 3-(N,N-dimethylN-hexadecyl ammonio-Z-hydroxy propane-l-sulfonate).

It will be understood that the above examples of supplementary surfactants are by no means comprehensive. Numerous other surfactants are known to those skilled in the art and are set forth in such familiar references as Surface Active Agents by A. M. Schwartz and James W. Perry. It will be further understood that the use of such surfactants will be in accordance with conventional, wellunderstood practices of detergent formulation. For example, cationic and anionic detergents will not normally be employed in combination due to recognized problems of precipitation of insoluble products.

Since the alkali metal ethane tetracarboxylate builder is substantially totally bio-degradable, preferably the surfactant chosen and any supplemental builder utilized will be similary bio-degradable in order to provide an overall formulation of maximum biodegradability. In particular, the use of surfactants exhibiting at least biodegradability (as determined by appropriate analytical techniques) under the conditions of the SDA Biodegradation Subcommittee test described in Journal of the American Oil Chemists Society, 42 986-993 (1965) are preferred. Examples of surfactants which are satisfactorily biodegradable includedinear alkylbenzene sulfonates, linear primary alcohol ethoxylates, linear primary alkyl sulfates and linear alkanes vicinally substituted with ethoxylate or hydroxy and ethoxylate groups.

In accordance with general practice, the ratio of the detergency builder components to the surfactant components will be in the range of from 1:2 to about 12:1 by weight.

In addition to surfactant and builder components, the detergent formulations of this invention may contain fillers such as sodium sulfate and minor amounts of bleaches, dyes, optical brighteners, soil anti-redeposition agents, perfumes and similar conventional detergent formulation additives.

The invention is further illustrated by the following Examples wherein all parts and percentages are by weight unless otherwise indicated.

EXAMPLE I Detergent formulations are prepared containing about 17 parts linear sodium alkylbenzene sulfonate having an average molecular weight of about 230; 8.5 parts silicate having a 1:2 ratio of Na OzSio 24.5 parts sodium sulfate and 50 parts tetra sodium ethane-1,1,2,2-tetracarboxylate. This composition is compared in cleaning effec- -tiveness on polyester/cotton and cotton fabrics with an 4 EXAMPLE II 1 A sample of ethane-1,1,2,2-tetracarboxy1ate is tested for biodegradation under the conditions described in the semi-continuous activated sludge test described in Journal of the American Oil Chemists Society, 42, 986-993 (1965); 46, 432440 (1969) and in the CO evolution test described by Thompson and Duthrie, Journal of the Water Polution Control Federation, 40, 306-319 (1968) and is found to be readily biodegradable using carbon analysis.

rWhat is claimedis:

1. A detergent composition consisting essentially of at least 8% by weight of a surfactant selected from the group consisting of anionic, nonionic, Zwitterionic, ampholytic and amphoteric surfactants and from 1% to by weight tetra alkali metal ethane-1,1,2,2-tetracarboxylate detergency builder, the ratio of said builder to surfactant being from 1:2 to 12:1 by weight. 1

2. The composition of claim 1 wherein said tetra alkali metal ethane-1,1,2,2-tetracarboxylate is tetra sodium ethane- 1 1,2,2-tetracarboxylate.

3. The composition of claim 2 wherein said tetra sodium ethane-1,1,2,2-tetracarboxylate is present in an amount of from 5% to 40% by weight.

References Cited UNITED STATES PATENTS 3,689,418 9/1972 Harken 25289 WILLIAM E. SCI-IULZ, Primary Examiner US. Cl. X.R. 252-90 

